Method and apparatus for the attachment of a fastener element to a component, in particular to a sheet metal part

ABSTRACT

A method and an apparatus for the attachment of a fastener element to a component, for example a sheet metal part, wherein the fastener element has an axis of symmetry, a head part having a contact surface which enters into contact with the component, a fastening section having a thread and also at least one undercut which receives the material of the component, and wherein the material of the component is pressed against the contact surface and into the undercut by means of a first tool having a die button shape matching the design of the fastener element, are characterized in that a local force is exerted on the head part of the fastener element or onto the tool to the side of the axis of symmetry and is moved circularly around the axis of symmetry while simultaneously carrying out a relative feed movement between the tool and the fastener element between which the component is arranged in order to press the material of the component into the undercut.

BACKGROUND OF THE INVENTION

The present invention relates to a method for the attachment of afastener element to a component, for example a sheet metal part, whereinthe fastener element has an axis of symmetry, a head part having acontact surface which enters into contact with the component, afastening section having a thread and also at least one undercut whichreceives the material of the component, and wherein the material of thecomponent is pressed against the contact surface and into the undercutby means of a first tool having a die button shape matching the designof the fastener element.

A method and an apparatus of the initially named kind are extremelywell-known in the field of attachment of the fastener elements to sheetmetal parts. For example the European patents 0 678 679 and 0 958 100describe how a fastener element which is available in commerce under thedesignation EBF from the company Profil Verbindungstechnik GmbH & Co. KGcan be attached to a sheet metal part. Furthermore, the European patents0 759 510 and 0 957 273 describe how variants of the so-called nutelements of the company Profil Verbindungstechnik GmbH & Co. KG can beattached to sheet metal parts. The above-described elements arefrequently termed press-in elements because they do not have any rivetsection which has to be beaded over.

In order to carry out the previously known methods presses withconsiderable pressing forces are mainly used which take care of theattachment of the fastener element to the sheet metal parts and indeedin particular when the sheet metal part is also to be given a specificshape in the press.

Not only elements of the company Profil Verbindungstechnik GmbH & Co. KGare attached to sheet metal parts in this way and means but rather alsoa series of further fastener elements from other competitors. It is alsoknown, instead of using a press for the attachment of the fastenerelements, to secure these in C-frames and/or by means of robots to sheetmetal parts and in both cases corresponding force-generating devicesmust be present which often have to produce forces in tons in twofigures.

Using such apparatuses the fastener elements are attached in one stroketo the sheet metal part, the process thus takes place relativelyquickly.

There are, however, a large number of possible applications in smallerand larger workshops, for example for the manufacture of smaller serieswhen no heavy presses or the other named devices (C-frames or robots)are available, either because the corresponding companies do not havesuch devices or because these are otherwise fully employed.

BRIEF SUMMARY OF THE INVENTION

It is thus the object of the present invention to propose reliablemethods and apparatus which are able to attach fastener elements of theinitially named kind to sheet metal parts without considerable forcesbeing required for this, so that companies are also in a position, evenwithout high investments in relatively heavy equipment, to attachfastener elements to components, in particular to sheet metal partsreliably, and with the method of the invention and the apparatusaccording to the invention being able to be used for a large number ofdifferent fastener elements.

Although the invention is primarily intended for use with sheet metalparts there are also other components such as components of plastic orin the form of laminates or cast parts of ductile materials which can beprocessed by means of the present invention.

In order to satisfy this object a method of the initially named kind isprovided which is characterized in that a local force is exerted on thehead part of the fastener element or onto the tool to the side of theaxis of symmetry and is moved circularly around the axis of symmetrywhile simultaneously carrying out a relative feed movement between thetool and the fastener element between which the component is arranged inorder to press the material of the component into the undercut.

The fastener element can be a bolt element, for example an EBF element,with the thread being formed on a shaft part of the fastener element andwith the shaft part being guided through a pre-holed component prior tothe exertion of the local force for the movement of the material of thecomponent into the undercut.

Alternatively the fastener element can be a nut element, for example anRSU element, with the thread being formed as a threaded bore of thefastener element and optionally being arranged in the head part, and themethod can be carried out with a holed component or an unholedcomponent, which is in principle also possible with a bolt element. Itshould be pointed out that with a nut element which is guided through apre-holed component the thread can be cut subsequently, i.e. after theattachment of the element to the component, by the use of a threadforming or thread cutting screw.

Thus, according to the invention, instead of using a large rapidlyacting force a substantially lower force is used which acts locally onthe fastener element and/or on the component, and indeed over acomparatively long time (which can however straightforwardly lie in therange of seconds), with the force being moved progressively about theaxis of symmetry of the fastener element and acting locally on thefastener element or on the sheet metal part until the attachment, i.e.the hooking of the material of the component to the fastener element orto the undercut or undercuts that is or are provided is completed. Sincethe force that is used is significantly smaller than the forcespreviously used the apparatus required to carry out the method issubstantially less loaded and can accordingly be made lighter and morecompact and requires less material than was previously necessary.

Furthermore, on carrying out the method, it is possible to operate withdie buttons which are identical to the die buttons previously used forthe corresponding elements, or which have only been insignificantlymodified so that proven systems which have been tested in practice cancontinually be used with the new method and with the new apparatus.

Particularly preferred variants of the method of the invention and alsoof the corresponding apparatuses can be seen from the patent claims andalso from the further description.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The invention will subsequently be explained in more detail by way ofexample only with reference to the drawings and with reference toembodiments. In the drawings:

FIG. 1A shows a first embodiment according to the invention of theattachment of a bolt element known per se to a sheet metal partimmediately prior to the start of the reshaping of the sheet metal part,

FIG. 1B shows an illustration according to FIG. 1A however just at theend of the shaping of the sheet metal part,

FIGS. 2A and 2B show Figures corresponding to FIGS. 1A and 1B but of avariant of the method of the invention and of the apparatus of theinvention,

FIGS. 3A and 3B show Figures corresponding to FIGS. 1A and 1B but of afurther variant of the method of the invention and of the apparatus ofthe invention,

FIGS. 4A and 4B show Figures corresponding to FIGS. 1A and 1B but ofanother variant of the method of the invention and of the apparatus ofthe invention,

FIG. 5A show a first embodiment according to the invention of theattachment of a nut element known per se to a sheet metal part justbefore the start of the reshaping of the sheet metal part,

FIG. 5B shows an illustration corresponding to FIG. 5A but just at theend of the reshaping of the sheet metal part,

FIGS. 6A and 6B show Figures corresponding to FIGS. 5A and 5B but of avariant of the method of the invention and of the apparatus of theinvention,

FIGS. 7A and 7B show Figures corresponding to FIGS. 5A and 5B but of afurther variant of the method of the invention and of the apparatus ofthe invention, and

FIGS. 8A and 8B show Figures corresponding to FIGS. 1A and 1B but ofanother variant of the method of the invention and of the apparatus ofthe invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1A and 1B an apparatus 10 is shown which is designedin order to carry out a method for the attachment of the fastenerelement 12 to a pre-holed plastically deformable component 13, forexample to a sheet metal part. The fastener element has a head part 14and a shaft part 16 having a thread which is arranged concentric to anaxis of symmetry 18 of the fastener element and which merges via acontact surface 22 extending in the radial direction into the head part14. The fastener element is in this specific case an EBF bolt element ofthe company Profil Verbindungstechnik GmbH & Co. KG, so that thefastener section, which enables the later attachment of a furthercomponent to the component assembly consisting of the bolt element andthe first component by a nut screwed onto the shaft part 16, is realizedhere by a thread arranged concentric to the axis of symmetry. Thefastener element illustrated here is to be understood as beingrepresentative for a large number of different elements and has,moreover, at least one undercut which receives the material of thecomponent. As shown in FIG. 1B the material of the component 13 ispressed against the contact surface 22 and into the undercut 24 by meansof a first tool 26 having a die button shape matched to the design ofthe fastener element, the tool here being a customary die button for EBFelements.

According to the invention a local force K is exerted onto the head part14 of the fastener element 12 to the side of the axis of symmetry 18.The position of this force is moved circularly around the axis ofsymmetry and at the same time a relative feed movement takes place inthe direction of the arrow 28 between the tool 26 and the fastenerelement between which the component is arranged, in order to press thematerial of the component into the undercut 24.

The fastener element 12 has, in addition to the radial undercut 24,which can be formed by the thread 15 in the region of the head part, anaxial ring groove 34 or concave fields in the contact surface 22. Theshaft part 16 of the fastener element is passed through a ring collar 35surrounding the hole of the pre-holed component 13 from the side of thecomponent remote from the ring collar 35.

The die button 26 has a central ring projection 36 with an at leastsubstantially conical inner surface 38 which presses the material of thering collar 35 radially inwardly into the undercut 24, as can be seenfrom FIG. 1B. Furthermore, the ring projection presses the sheet metalmaterial into the ring groove 34.

The local force K is exerted onto the head part 14 of the fastenerelement 12 with a second tool 40 which is arranged in an inclinedposition 42 related to the axis of symmetry 18 and is rotated about theaxis of symmetry 18 (arrow 43). The second tool 40 has a conical endface 44 facing the head part 14 of the fastener element and operates inthis example directly on the head part 14 of the fastener element 12.

The relative axial feed movement (arrow 28) between the die button 26which receives the head part 14 and the tool 40 is carried out until thering collar 35 has been completely beaded over and brought into contactwith the fastener element 12 as is shown in FIG. 1B. Since the tool 40is aligned with the inclined axis 42 and is rotated about the axis ofsymmetry 18 the inclined axis 42 continuously moves and can for examplebe found at 42′ at a later point in time.

At any point in time during the re-shaping of the sheet metal part thedie button projection 36 is in contact with the ring collar over only acomparatively small surface which progressively moves around the axis ofsymmetry 18 on rotation of the tool 40 and leads to a progressive localdeformation of the ring collar. The simultaneously occurring feedmovement in the arrow direction 28 leads, in combination with thisrotary movement, to a progressive hooked engagement of the sheet metalmaterial with the ring groove or the concave fields in the contactsurface, i.e. in the corresponding side of the head part and also withthe undercut, so that this hooking can be completed with only a fewrotations of the tool 40 in total.

For carrying out this process, apparatus (not shown) similar to a pillardrilling machine or drill press can be used in which the die button 26is mounted on the table of the pillar drill and the second tool 40 onthe drilling head of the pillar drill, and indeed in a positioncorresponding to the oblique axis 42 which ensures the rotation aboutthe axis of symmetry 18. The feed movement can take place by hand bymanual feeding of the drilling head towards the table (as usual inpillar drilling) or by a drive which moves the table towards thedrilling head or the drilling head towards the table. Naturally specialapparatuses can also be provided which ensure the required movements.The sheet metal part can be positioned by hand or by a small robot ontothe shaft part 16 of the bolt element and onto the die button, with theshaft part of the bolt element entering into a central bore 48 of thedie button 40. The sheet metal part can be secured or clamped to thetable or to a support (not shown) adjacent to or disposed surroundingthe die button 26, providing the die button 26 is not itself used forthis purpose, which is entirely possible.

During the re-shaping of the sheet metal any features providing securityagainst rotation which are provided at the fastener element, for examplein the region of the contact surface 22 and/or at the transition fromthe shaft part 16 into the contact surface 22 can be brought intoengagement with the component 13. Such features providing securityagainst rotation can for example have the form of radial ribs whichbridge the ring groove 34 and subdivide this into concave fields, as isthe case with an EBF bolt.

In a further development of the method the second tool 40 can be rotatednot only about the axis of symmetry 18 of the fastener element butrather simultaneously about the inclined axis 42 which is defined by theinclined position of the second tool. An additional rotary movement ofthis kind is indicated by the arrow 43 in FIG. 1A.

A further variant of the method and of the apparatus will now bedescribed with reference to FIGS. 2A and 2B. In the description of FIGS.2A and 2B the same reference numerals will be used for parts as werepreviously used for corresponding parts or parts having the samefunction in the embodiment of FIGS. 1A and 1B. It will be understoodthat the same description applies to these parts as for correspondingparts of the embodiment of FIGS. 1A and 1B, unless something to thecontrary is expressed. This convention will be used throughout thefurther description. When only small differences are present betweencorresponding parts, the parts will be identified by the same referencenumerals but additionally supplemented with a prime, such as ′, ″, ′″,″″ or ″″.

In this variant the second tool 40 operates via a cylindricalintermediate piece 50 on the head part 14 of the fastener element 12.The cylindrical intermediate piece 50 and a front section 52 of thesecond tool 40 facing the cylindrical intermediate piece are guided by atubular guide part 54 with some radial clearance.

The end face 44 of the second tool 40 facing the head part 14 of thefastener element 12 has an at least substantially linear contact 56 withthe intermediate piece 50.

Whereas the second tool 40 operates in the embodiment of FIGS. 1A and 1Bon a ring surface 57 of the head part of the fastener element thecylindrical intermediate piece 50 does this in the embodiment of FIGS.2A and 2B.

In this embodiment any features providing security against rotationwhich are provided on the fastener element, for example in the region ofthe contact surface and/or at the transition from the shaft part intothe contact surface are also brought into engagement with the component13 during the re-shaping movement.

The possibility also exists here of rotating the second tool 40 not onlyabout the axis of symmetry 18 of the fastener element but rathersimultaneously also about the axis of inclination 42 which is defined bythe inclined position of the second tool 40.

The design of the die button 26 and the reception of the shaft part 16of the fastener element in the bore 48 of the die button are identicalto the embodiment of FIGS. 1A and 1B and they are not be especiallydescribed here.

A third method according to the invention and a third apparatusaccording to the invention for the attachment of a fastener element,which has already been described in detail in connection with FIGS. 1Aand 1B, are shown in FIGS. 3A and 3B. In the description of FIGS. 3A and3B the same reference numerals will be used for parts as were previouslyused for corresponding parts or parts having the same function in theFIGS. 1A and 1B embodiment. It will be understood that the samedescription applies to these parts as for the corresponding parts of theembodiment of FIGS. 1A and 1B, unless something to the contrary isexpressed.

As shown in FIG. 3A the head part 14 of the fastener element 12 isreceived in a cut-out 60 of a tool 62 the end face 64 of which supportsthe component 13 at least substantially at the level of the contactsurface 22. The local force K is exerted onto the component 13, inparticular onto its ring collar 35 via a tool 26′ which has at its lowerend face in FIG. 1A a shape corresponding to the end face of the diebutton 26 of the previous embodiments, with the shape of the ringprojection 36′ having been slightly eased, i.e. relieved, relative tothe ring projection 36 of the die button 26 of FIGS. 1A, 1B, and 2A, 2Bin order to take account of the swashing movement of the tool 26′. As aresult of the small differences the tool is designated with thereference numeral 26′ and the ring projection with its inner surfacewith the reference numerals 36′ and 38′ respectively. The tool 26′ isarranged in an inclined position related to the axis of symmetry 18 andis rotated in the arrow direction 43 about the axis of symmetry 18.

Here the first tool 26′ operates directly on the component in the regionof the fastener element.

In this embodiment, during the re-shaping movement, any featuresproviding security against rotation which are attached to the fastenerelement, for example in the region of the contact surface and/or at thetransition from the shaft part into the contact surface are also broughtinto engagement with the component 13.

Here the possibility also exists of not only rotating the tool 26′ aboutthe axis of symmetry of the fastener element but rather simultaneouslyalso about the axis of inclination 42, which is defined by the inclinedposition of the tool 26′.

A fourth method according to the invention and a further fourthapparatus according to the invention for the attachment of the fastenerelement, which has already been described in detail in connection withthe FIGS. 1A and 1B are illustrated in FIGS. 4A and 4B. In thedescription of FIGS. 4A and 4B the same reference numerals will be usedfor parts as were previously used for corresponding parts or partshaving the same function. It will be understood that the samedescription applies for these parts, as for the corresponding parts ofthe embodiments, unless something is expressed to the contrary.

This fourth embodiment is characterized in that the first tool 26″ isformed as a cylindrical intermediate piece which operates on a componentin the region of the fastener element and in that a third tool 70 exertsthe local force K on the first tool 26″.

The first tool 26″ and a front section 72 of the third tool facing thiscylindrical intermediate piece are guided by a tubular guide part 54with some radial clearance. The end face 74 of the third tool 70 facingthe component has a conical shape and an at least substantially linearcontact 76 with the side of the first tool 26″ remote from thecomponent.

In this embodiment any features providing security against rotationwhich are provided on the fastener element, for example in the region ofthe contact surface and/or at the transition from the shaft part intothe contact surface are also brought during the re-shaping movement intoengagement with the component 13.

Here the possibility also exists of not only rotating the third tool 70about the axis of symmetry of the fastener element but rathersimultaneously also about the axis of inclination 42 which is defined bythe inclined position of the second tool 40.

A further variant of the method of the invention and of the apparatus ofthe invention is shown in FIGS. 5A and 5B. The fastener element 12′ hereis a nut element, with the thread being formed as a threaded bore 15′ ofthe fastener element and optionally being able to be arranged in thehead part 14. The method can in this embodiment, as also in the laterembodiments according to FIGS. 6A, 6B; 7A, 7B; and 8A, 8B be carried outwith a holed or non-holed component 513′.

In the subsequent description of the further embodiments the samereference numerals will be used for parts which have the same functionas parts in the first four embodiments and it will be understood thatthe previous description applies in analogous manner for these parts. Asis evident the four further embodiments according to the Figures whichhave yet to be described can be understood almost identically to thefirst four embodiments so long as one takes account of the fact thatthey relate to a nut element instead of a bolt element, with the nutelement being designed differently than the bolt element, above all inthe region of the attachment to the sheet metal part. The element shownhere is an RSU element as recited above. Other than in the embodimentaccording to the further Figures it is however also possible for thecomponent to be a non-holed component which is pierced during theattachment of the nut element. Nonetheless the nut element can also beused with a pre-holed component and indeed with a pre-holed componentwhich is provided with a ring collar such as 35 according to theprevious Figures.

The nut element in all the following examples is an RSU element asrecited above. According to this the fastener element 12 has, in thehead part 14, radially inside an at least substantially ring-likecontact surface 22, a recess 80 with at least one radial undercut, forexample a ring-like undercut or preferably (as realized in the actualRSU element) with discrete undercuts 82 formed locally at a wall of thecut-out, with which corresponding recesses 84 provided locally in thering-like contact surface 22 are preferably associated. Through theaction of the first tool 26″ having the die button shape the material ofthe component is pressed into the undercut(s) 82 and into the recesses84.

When the component 13 is a pre-holed component the first tool 26″ havingthe die button shape presses the sheet metal material around the collarof the hole produced by the pre-holing into the cut-out 80.

Alternatively, when the component 13 is a pre-holed component with aring collar 35 which surrounds the hole produced by the pre-holing andwhich is introduced into the cut-out 80, the first tool 26′″ having thedie button shape presses the sheet metal material in the region of thering collar 80 into the undercut(s) 82.

The tool 26′″ having the die button shape presses the material of thecomponent also into the recesses 84 provided locally in the ring-likecontact surface.

For the above described purposes the first tool 26′″ having a die buttonshaped has a central, tubular, optionally conically shaped projection 86which presses the material of the component radially outwardly into theundercut(s) 82 and optionally into the cut-out 80 or into the recesses84.

The piercing of the sheet metal component takes place in thesubsequently described embodiments in that the component is a non-holedcomponent and the tool which receives the fastener element 12, i.e. thesecond tool has a pin 90 disposed concentric to the fastener elementwhich passes through the bore 92 of the fastener element 12′ and thefree end of which 94 cooperates with the hollow first tool 26′″ havingthe die button shape in order to cut out a die button 96 from thecomponent 13′, with the slug being disposed of through the central bore92 of the tool 26′″ having the die button shape. The pin 90 can berealized as a preceding hole punch which is used to pierce the sheetmetal prior to the start of the swashing movement of the tool 40′ toform the sheet metal around the hole into the cut-out of the element.The force required to actuate the hole punch is relatively low and caneasily be realized using a hand press action in the apparatus for themovement of the pin 90. E.g. in a conventional press, with an RSU nutwith a 6 mm thread size and using a sheet metal component of 0,8 mmthickness a force of approximately 400 Kgf would be needed to punch theslug from the sheet metal whereas a force of 6000 Kgf would be needed toform the sheet metal around the hole into the cut-out in the element.Thus the punching of the hole in the component is not problematic evenin a lightweight apparatus such as can be used to form the sheet metalinto the cut-out of the component in accordance with the presentteaching. The above considerations apply to all variants in accordancewith the present teaching in which a hole punch is used to form a holein the sheet metal part prior to the attachment of the fastener elementto the same. The pin can assist in centering the element but should havesufficient clearance relative to the bore of the fastener element not tointerfere with the swashing movement of the fastener element.

In the embodiment of FIGS. 5A and 5B the first tool having the diebutton shape is a normal die button for the attachment of an RSUelement. The local force K is exerted onto the head part of the fastenerelement with the second tool which is disposed in an inclined position42 related to the axis of symmetry 18 and is rotated about the axis ofsymmetry 18.

The second tool 40′ has a conical face 98 which faces the head part 14of the fastener element 12′ and a conical end face 99. In thisembodiment the conical face 98 of the second tool 40′ operates directlyon the head part 14 of the fastener element 12.

As an alternative to this the second tool 70′ can operate according tothe embodiment of FIGS. 6A and 6B via a cylindrical immediate piece 50on the head part 14 of the fastener element 12′.

As previously the cylindrical intermediate piece 50 and a front section72 of the second tool 70 facing the cylindrical intermediate piece canbe guided by a tubular guide part 54 with some radial clearance. Theconical end face 74 of the second tool 70 facing the head part 14 of thefastener element 12′ has an at least substantially linear contact 76with the cylindrical intermediate piece 50. Here also the cylindricalintermediate piece 50 operates on a ring surface 14′ of the head part ofthe fastener element.

In the next embodiment according to FIGS. 7A and 7B the head part 14 ofthe fastener element 12′ is received in a cut-out 60′ of a tool 62′, theend face 64′ of which supports the component 13′ at least substantiallyat the level of the contact surface 22′. The first tool 26″″, whichexerts the local force K onto the component 13′ is disposed in aninclined position 42 radial to the axis of symmetry 18 and is rotatedabout the axis of symmetry 18. Here the first tool 26″″ operatesdirectly on components 13′ in the region of the fastener element 12′.

In the last embodiment according to FIGS. 8A and 8B the first tool 26′″″having the die button shape is formed as a cylindrical intermediatepiece which operates on the component 13′ in the region of a fastenerelement 12′. The tool 70′ exerts the local force K onto the first tool26′″″.

Here also the first tool 26′″″ and a front section 72′ of the tool 70′facing it are guided by a tubular guide part 54′ in some radialclearance. Furthermore, the end face 76′ of the first tool which facesthe component also has an at least substantially linear contact with thefirst tool 26′″″ here. The tool 70′ has for this purpose a conical endface facing the head part of the fastener element.

In all the embodiments the fastener element can have features providingsecurity against rotation in the region of the contact surface and/or ofthe transition from the contact surface into any shaft part that isprovided and/or in the region of a hollow recess of the fastenerelement, with the material of the component also being brought intoengagement with the features providing security against rotation by theaction of the local force and the feed movement, with the featuresproviding security against rotation optionally also being able to berealized by the at least one undercut or by recesses in the contactsurface.

Finally it should be pointed out that all steel or aluminum or magnesiumsheet metal parts can be considered for the sheet metal parts which havedeep drawing qualities, whereas somewhat stronger materials are used forthe fastener element.

In all embodiments all materials can be named as an example for thematerial of the fastener elements which achieve strength values of class8 according to the ISO standard in the context of cold deformation, forexample a 35B2 alloy according to DIN 1654. The so formed fastenerelements are suitable amongst other things for all commerciallyavailable steel materials for drawing quality sheet metal parts as alsofor aluminum or its alloys. Aluminum alloys, in particular those withhigher strength, can also be used for the fastener elements, for exampleAlMg5. Fastener elements of higher strength magnesium alloys such as forexample AM50 can also be considered.

1. A method for the attachment of a fastener element to a componenthaving a pre-formed hole and material surrounding said hole, wherein thefastener element has an axis of symmetry, a head part having a contactsurface which enters into contact with the component, a fasteningsection having a thread, with the thread being formed as a shaft part ofthe fastener element, and the fastener element also having at least oneundercut which receives the material of the component, and wherein thematerial of the component is pressed against the contact surface andinto the undercut by means of a first tool having a die button shapematching the design of the fastener element, wherein a local force isexerted on the head part of the fastener element or onto the first toolto the side of the axis of symmetry and is moved circularly around theaxis of symmetry while simultaneously carrying out a relative feedmovement between the first tool and the fastener element between whichthe component is arranged in order to press the material of thecomponent into the undercut and wherein said shaft part is guidedthrough said pre-formed hole prior to exerting the local force for themovement of the material of the component into the undercut, and whereinthe head part of the fastener element is received in a cut-out of asecond tool the end face of which supports the component at leastsubstantially at the level of the contact surface, and wherein the localforce is exerted onto the component with the first tool which isdisposed at an inclined position relative to the axis of symmetry and isrotated about the axis of symmetry.
 2. A method according to claim 1,wherein the fastener element is a bolt element.
 3. A method according toclaim 1, wherein the end face of the first tool facing the component hasa substantially linear contact with the component.
 4. A method accordingto claim 1, wherein the fastener element has an axial ring groove orconcave fields in the contact surface and also a radial undercut whichcan be formed by the thread in the region of the head part, and whereinthe fastener element is passed through a ring collar surrounding thehole of the pre-holed component from the side of the component remotefrom the ring collar.
 5. A method according to claim 1, wherein thefirst tool having a die button shape has a central ring projection withan at least substantially conical inner surface which presses thematerial of the ring collar radially inwardly into the undercut.
 6. Amethod according to claim 1, wherein the component is a pre-holedcomponent with a ring collar surrounding the hole produced by thepre-holing which is introduced into the cut-out, and wherein the firsttool having the die button shape presses the sheet metal material in theregion of the ring collar into the concave fields.
 7. A method accordingto claim 1, wherein the fastener element has features providing securityagainst rotation in the region of the contact surface and/or of thetransition from the contact surface into any shaft part that is presentand/or in the region of a hollow recess of the fastener element, whereinmaterial of the component is brought by the action of the local forceand the feed movement also into engagement with the features providingsecurity against rotation.
 8. A method according to claim 1, wherein thecomponent is a sheet metal part.